Device used to guide a space craft into finding an inhabited planet or colony on a planet.

"Now, what happened to the official, licensed, authorized colony here?" asked Bordman briskly. "License issued eighteen months ago. There was a landing of colonists with a drone-fleet of equipment and supplies. There've been four ship-contacts since. There should be several thousand robots being industrious under adequate human supervision. There should be a hundred-mile-square clearing, planted with food-plants for later human arrivals. There should be a landing-grid at least half-finished. Obviously there should be a space-beacon to guide ships to a landing. There isn't. There's no clearing visible from space. That Crete Line ship has been in orbit for three days, trying to find a place to drop me. Her skipper was fuming. Your beacon is the only one on the planet, and we found it by accident. What happened?"